The field of ACTH regulation and action is one that has been the subject of major new advances in the past five years, and is a field which well exemplifies the progress brought about by, and the continued need for, interdisciplinary studies. Such interdisciplinary studies are reflected in the proposed program which will bring together an international group of scientists and clinicians who have made major recent contributions to the fields of (a) anterior pituitary electron microscopy and immunocytochemistry; (b) structure-function relationships of ACTH and related peptide hormones; (c) assay of ACTH; (d) the effect of ACTH on adrenal cortical structure and biochemistry; (e) its effect on neural transmission and behavior, (f) the effect of neurotransmitter substances on diverse aspects of ACTH secretion; (g) the chemical nature of the presumed cortiocotropin releasing factor; and (h) disease state characterized by abnormalities in ACTH secretion. Research is rapidly progressing in all of these areas, and major advances are anticipated in many of these areas in the coming year. There has been no meeting of scientists involved in or any publication related to an overall survey of these fields for the past four years. It is to be expected that newer insights brought about such a meeting, seen from different points of view, will serve to point out new interrelations, new techniques available and new areas for future research.